Wet cutting saws are typically used to cut through hard materials such as concrete, bitumen, rock, bricks and tiles. Water (or another suitable liquid) is fed onto the circular blade of the wet cutting saw primarily to act as a coolant for the blade as the heat created by the friction of the blade as it rotates to cut the hard materials is quite substantial. The water is also added to clean the teeth of the saw blade (should it have teeth) and to flush cuttings out of the cut formed by the blade. Typically, the water used with the wet cutting saw forms a slurry with particles of the hard material which are formed during the cutting process.
In many applications of wet cutting saws, it is necessary to provide adequate control over flow of the water and slurry away from the wet cutting saw. Such applications may include when cutting inside buildings such as shopping centres and in circumstances where it is necessary to protect the environment from such flows. Conventionally, this has been achieved by vacuuming up the slurry and water run-off which flows away from the blade. For small wet cutting saws, this may be readily achieved by a single person operating a hand held vacuum.
Recent developments in wet cutting saws have seen a significant increase in the power of the saws. These more powerful cutting saws more readily cut through concrete, rock and other such hard materials thus enabling faster use of the saws. One consequence, however, of these more powerful saws is that more water is required to cool the blade, which in turn means that controlling the flow of water and slurry away from the blade is more difficult. As a result, either the speed of use of the wet cutting saw is limited, despite its greater power, or operators of the cutting saws have to employ more than one manually operated vacuum or even industrial vacuum pumps to control the water and slurry flow away from the blade (at considerable additional cost to the operator).
U.S. Pat. No. 5,477,844 proposes a solution to the problem of controlling water and slurry flow away from the blade based on use of a vacuum. The wet cutting saw of U.S. Pat. No. 5,477,844 has a saw blade house within a blade guard. Expandable bellows fit over the blade guard and are fixed to a drag bar which can be lowered onto the ground. The drag bar has a vacuum chamber open to the space inside the slurry containment section (where the blade is located). Application of a vacuum on the vacuum chamber draws the water and slurry into the chamber and then to a separator tank where the solids can be separated from the water. However, the wet cutting saw of U.S. Pat. No. 5,477,844 has not found commercial acceptance. Furthermore, it does not resolve the problem of requiring high vacuuming power for high flows of water to more powerful cutting saws.